Some things are defined by a list of (measurable) properties/attributes. Some things are defined by their function/use. A "chair" for example. (A rock or a pile of hay might be used as a chair.)
What a thing is may well change over time. From measuring things like size and shape and mass/weight we have moved on to measuring electric charge and then quantum mechanical "spin." We have new measurements with which we can describe an object. We also find new functions for things. Water or dirt can now be used to shield us from nuclear radiation. A computing device that once crunched numbers may now be used to manipulate symbols and conduct social discourse.
If a mind is given greater memory and more processing speed it will likely form more and different categories with which to describe its experiences and its world. It may abstract and compress and generalize less as it may have less need to do so. In all these ways what is real changes.